Geometrically thick equilibrium tori around a Schwarzschild black hole in swirling universes

TL;DR

This paper investigates the structure and properties of thick equilibrium tori around Schwarzschild black holes in swirling universes, revealing how background swirl affects disk size, symmetry, and matter excretion.

Contribution

It introduces a new model of equilibrium tori in swirling universes, highlighting the effects of background swirl on disk structure and symmetry, which was not previously studied.

Findings

Equilibrium tori exist only for small swirling parameters.

Increasing swirl reduces disk size and enhances matter excretion.

Swirling causes asymmetry in the disk and deviation from equatorial symmetry.

Abstract

We study geometrically thick non-self gravitating equilibrium tori orbiting a Schwarzschild black hole immersed in swirling universes. This solution is axially symmetric and non-asymptotically flat, and its north and south hemispheres spin in opposite directions. Due to repulsive effects arising from the swirl of the background spacetime, the equilibrium torus exists only in the case with the small swirling parameter. With the increase of the swirling parameter, the disk structure becomes small and the excretion of matter near the black hole becomes strong. Moreover, the odd $Z_2$ symmetry of spacetimes originating from the swirling parameter yields that the orientation of closed equipotential surfaces deviates away from the horizontal axis and the corresponding disk does not longer possess the symmetry with respect to the equatorial plane. These significant features could help to further understand the equilibrium tori and geometrically thick accretion disks around black holes in swirling universes.